1. Field of the Invention
The present invention generally relates to a waterproof structure of an electronic device.
2. Description of Related Art
Recently, touch panels have been applied in many electronic devices, such as mobile phones, laptops, MP3, personal digital assistants (PDA), global positioning system (GPS), super mini computers (UMPC) and other portable electronic devices. The technology of touch panel on the market can be commonly divided into restive one, capacitive one, infrared one and ultrasound one. So far, the resistive and the capacitive touch panels play the main role on the market.
If the aforementioned electronic device is used in a more harsh environment, such as waterproof function, sand-proof function, corrosion-resistant function and anti-vibration function, etc., the electronic device requires some additional designs to meet the relevant usage needs, for example, to reach a required waterproof grade and anti-vibration.
In other words, to meet the usage needs, the aforementioned electronic device must meet the more strict design specifications. Taking the waterproof effect as an example, in general, an electronic device with a touch screen mostly employs waterproof tapes disposed between the housing and touch screen thereof, and the sealing effect between the touch screen and the housing is achieved by squeezing the waterproof tapes during assembling. However, the employing of the waterproof tape is necessary for an electronic device with a resistive touch screen, but the waterproof tape in the assembling process would cause some relevant troubles.
For example, FIGS. 1 and 2 are local cross-sectional diagrams of an electronic device in the current technology, and FIGS. 3 and 4 show the states of the touch screen of the electronic device after being assembled in current technology respectively corresponding to FIGS. 1 and 2. Referring to FIGS. 1-4, a display element 120 of an electronic device 300 is a resistive touch screen which performs induction operation through a voltage-detecting method, wherein indium tin oxide (ITO) conductive glass 121 and PET (polyethylene terephthalate, briefly referred to as polyester or PET) conductive film 123 are the main raw materials of the display element 120. In addition, a plurality of spacers 121a are disposed between the upper transparent electrode and the lower transparent electrode to maintain a gap between the PET conductive film 123 and the conductive glass 121, while an adherent element 125 (for example, adhesive) located at both sides of the spacers 121a is adhered between the conductive glass 121 and the PET conductive film 123. When a finger, a stylus or other objects exerts a force onto the PET conductive film 123, the value of the capacitance between the PET conductive film 123 and the conductive glass 121 gets changed. However, during the assembling, when a fastener 140 is assembled to the housing 310, the fastener 140 clamps the display element 120 and a sealing member 330 (i.e., the aforementioned waterproof tape) therein such that the sealing member 330 gets deformed due to the squeezing action (as shown in FIG. 2). Further, the PET conductive film 123 is squeezed under the deformation of the sealing member 330 (as shown in an arrow head in FIG. 2) to push the PET conductive film 123 into a state shown in FIG. 4, i.e., both ends of the PET conductive film 123 are bulged and the portion between the both ends is collapsed.
Thus, the conductive glass 121 and the PET conductive film 123 after the electronic device 300 being assembled are quite close to each other, and further the upper electrode may be conductive with the lower electrode.
FIG. 5 is a schematic diagram of a touch screen in bad state. It can be seen from FIG. 5 that while a user normally touch manipulates onto a display surface 122 (for example, writing a “” Chinese character on the display surface 122), due to short-circuit between the upper and lower electrodes, the touch coordinates are disordered, and further fly-line happened as shown in FIG. 5.
Therefore, an issue for the relevant developers to care about is that how the touch function is normally performed of the electronic device 300 under the aforementioned circumstance.